JP2554184B2 - How to grind the blade of scissors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is to grind the contact points necessary for both blades in order to provide a contact pressure between the blades, and to grind the blade backs of both blades. It is about the method of giving by.

[Prior Art] Conventionally, for example, as shown in Japanese Utility Model Laid-Open No. 60-158568, in the scissors contact point structure, between the blade backs of the handle mounting portion that is closer to the base end than the opening / closing center shaft of both blades. A contact point portion is provided, and the pressure contact force of the contact point portion allows the scissors to be opened and closed while the blades are always in close contact with each other.

In addition, as a similar scissors contact point structure,
-18377 and Japanese Utility Model Laid-Open No. 55-159064.

[Problems to be Solved by the Invention] However, in any of the publications, formation of the contact point portion was very troublesome.

It is an object of the present invention to provide a method capable of forming a touch point portion at the same time when grinding the blade backs of both blades, so that the touch point portion can be easily formed.

Constitution of the Invention [Means for Solving the Problems] In view of this object, the present invention, as shown in the drawings of an embodiment described later, of the blade portion 8 which is on the tip side of the opening / closing center axis support hole 7 of the blade In the method of grinding a blade of scissors, which grinds the back 5 of the blade and the back 5 of the handle mounting portion 9 on the base end side of the support hole 7 with the rotary grindstone 6, the blade 4 is rotated relative to the rotating grindstone 6. Relative movement, the circular edge 6 of this rotary grindstone 6 is the back 5 of the blade.
In a group of circular arc loci C which are drawn so as to be continuous with each other in the relative movement direction, the line D connecting the bisectors, which is the largest cut in each circular arc locus C, is the back of the blade portion 8. 5 is ground so that both side edges 5a, 5b thereof are crossed, and a line F connecting one end side of each arcuate locus C away from the bisector D is attached to the handle so as to reduce the depth of cut. It passes through the back 5 of the part 9 and grinds so that both side edges 5a, 5b thereof intersect.

[Operation] By grinding the back 5 of the blade in this manner, the contact point 10 along the line F is formed on the back 5 of the handle mounting portion 9.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, a blade mounting plate 2 is fixed on a rotating body 1 which rotates on a horizontal plane, and a large number of blade positioning recesses 3 are formed on the outer periphery of the mounting plate 2. They are arranged symmetrically. A blade 4 is fitted in the positioning recess 3, and a back 5 of the blade is slightly projected upward.

A rotary grindstone 6 is provided on the moving path of each blade 4 above the rotary table 1. Center of rotation 6b of the whetstone 6
Is inclined by θ degrees on a vertical plane with respect to the center of rotation 1b of the turntable 1. The circumferential edge 6a of the rotary grindstone 6 can contact the back surface 5 of the blade 4 on the vertical plane 1c passing through the rotation center 1b of the rotary table 1. The blade 4 is composed of a blade portion 8 on the tip side of the rotation center shaft support hole 7 formed therein and a handle mounting portion 9 on the base end side. The opening / closing center shaft support hole 7 and the tip 8a of the blade portion 8a. The longitudinal direction A of the blade 4 along the line connecting and is inclined by α degrees on the horizontal plane with respect to the moving direction B of the blade 4.
When each blade 4 on the blade mounting plate 2 passes under the rotary grindstone 6 as the rotary body 1 rotates, the back edge 5 of the blade 4 is ground into a concave curved surface by the circumferential edge 6a of the rotary grindstone 6. .

In this case, the circular edge 6a of the rotary grindstone 6 draws an arc locus C as shown in FIG. 3 with respect to the back 5 of the blade of the blade 4. The largest cut is on the line D connecting the bisectors of the arc locus C. As shown in FIG. 4, the back 5 of the blade intersecting the bisector D is the same and has the largest cut.
The depth of cut becomes smaller as the distance from the bisector D increases. Both side edges 5a, 5 of the back of the blade 5 where this arc locus C intersects
Considering the space between b, the entire back surface 5 of the blade has a concave curved surface that curves in the width direction connecting both side edges 5a and 5b. Considering the intersection of the line E parallel to the bisector D and the side edges 5a, 5b, the cuts at those intersections are the same, and the farther the distance from the bisector D, the more the side edges 5a, 5b are cut. Get smaller. Therefore, the entire back surface 5 of the blade has the concave curved surface in the width direction as described above, and simultaneously has the concave curved surface that curves in the longitudinal direction A.

In particular, a line F connecting one ends of the arcuate locus C drawn by the circumferential edge 6a of the rotary grindstone 6 is located on the blade back 5 of the handle mounting portion 9 near the opening / closing center axis support hole 7. This line F is inclined with respect to the longitudinal direction A. The cut of the blade back 5 along this line arc F becomes the smallest, and the contact point portion 10 is formed on the blade back 5 along this line F.

When a pair of blades 4 having the above-mentioned concave curved surface on the blade back 5 are assembled together as shown in FIG. 5, the contact points 10 of the handle mounting portions 9 of both blades 4 intersect with each other and both blades A space is created between the blade backs 5 of the blade portions 8 of No. 4 and a contact pressure is applied between the blade portions 8 to obtain a good sharpness.

If the blade mounting plate 2 is replaced, the blade 4 of various conditions
Can also be accommodated.

Particularly, in the present embodiment, when the blade back 5 of the blade 4 is ground by the circular edge 6a of the rotary grindstone 6, the blade back 5 of the handle mounting portion 9 has a contact point 10 near the opening / closing center axis support hole 7 of the blade 4. Since the contact points 10 can be formed, the contact points 10 can be formed very easily.

The longitudinal direction A of the blade 4 is inclined with respect to the moving direction B of the blade 4, and the blade 4 is passed under the rotary grindstone 6 to obtain a desired concave curved surface on the blade back 5 of the blade 4. Therefore, the supply operation and the discharge operation of the blade 4 with respect to the rotary grindstone 6 are limited to one direction and are simplified, and not only the mechanism is very simple, but also it is difficult to mass-produce the blade 4 continuously. Is suitable.

Although the moving direction B of the blade 4 draws a circle in the above embodiment, it may be a straight line.

EFFECTS OF THE INVENTION According to the present invention, by simply grinding the blade back 5 of the blade 4,
Near the opening / closing center axis support hole 7 of the blade 4
The contact point portion 10 can be easily formed.

[Brief description of drawings]

FIG. 1 is a schematic front view showing a blade grinding apparatus according to this embodiment, FIG. 2 is a schematic plan view of the same, and FIGS. 3 and 4 show the relationship between the blade back of the blade and the arc locus of a rotary grindstone. Illustration,
FIG. 5 is a front view showing scissors in which both blades are assembled together. 1 ... Revolving base, 2 ... Blade mounting plate, 3 ... Blade positioning recess, 4 ... Blade, 5 ... Blade back, 6 ... Rotating whetstone, 6a ...
… Circumferential edge, 7 …… Opening / closing center axis support hole, 8 …… Blade part, 9…
… Handle attachment part, 10 …… Touch point part.

Claims (1)

(57) [Claims] 1. A blade backside (5) of a blade portion (8) that is on the tip side of the opening / closing center axis support hole (7) of the blade (4) and on the base end side of the support hole (7). Behind the blade (5) of the handle mounting part (9)
In the method of grinding a blade of scissors for grinding and with a rotating grindstone (6), the blade (4) moves relative to the rotating grindstone (6), and the circular periphery (6a) of the rotating grindstone (6) is a blade. In the arc locus (C) group drawn so as to be in contact with the back surface (5) and continuous in the relative movement direction, a line connecting the bisectors, which is the largest cut in each arc locus (C). Grind so that (D) passes through the back of the blade (5) of the blade (8) and intersects both side edges (5a, 5b) of the blade (8). Each arc locus going away (C)
The scissors are characterized in that a line (F) connecting one end side of each of the two ends is passed through the back of the blade (5) of the handle mounting part (9) to cross both side edges (5a, 5b) thereof. How to grind the blade.